The Sacagawea Dollar, introduced in 2000, is a United States coin that features a depiction of Sacagawea, a Shoshone woman who aided Lewis and Clark during their expedition. The 2018 San Francisco Sacagawea Dollars are part of the annual minting and typically have a proof finish, showcasing a higher quality strike and a polished appearance. These coins are sought after by collectors due to their historical significance and the artistry of their design.